This invention is a form of debris-flow control engineering that specifically relates to the design and application of an asymmetric debris-flow drainage channel that is used in special conditions in which the protected objects on both sides of the drainage channel have different design standards. Debris flow is one of the major geological hazards in the world, and the demand for debris-flow control engineering is increasing rapidly. Drainage channels are one of the main types of debris-flow control structures and are widely used in debris-flow hazard mitigation. At present, debris-flow drainage channels are completely symmetrical in terms of both structural design and materials used, a configuration that ignores the differences in the design standards of the objects that are to be protected on either side of the drainage channel. To accommodate the different design and protection standards that can be required on each side of a drainage channel using a symmetrical debris-flow drainage channel can easily result in excessive construction work and material waste. Furthermore, under low frequency debris flows of large-scale and high discharge, the debris-flow depth can exceed the height of the side wall of the drainage channel, overflowing the channel and destroying the area to be protected (settlements, buildings, factories, etc.) on both sides of the drainage channel.